Processing method for an image fiber

ABSTRACT

In the present invention, a deformation process is applied to a part of an image fiber, and when implementing improvement of the quality of the transmitted image, the improvement of the image quality in the center region and peripheral region of the image fiber in the radial direction is carried out to an equal degree, and a uniform improvement of the entire screen can be carried out. A processed part is formed having a deformation of all cores that is substantially identical by deforming in the radial direction or by deforming and twisting a part of an image fiber having a plurality of cores that function as pixels in the radial direction thereof. The image fiber can be manufactured by a processing in which by a part of the image fiber having a plurality of cores that function as pixels is heated, and deformed in the radial direction thereof or simultaneously deformed and twisted in the radial direction thereof this heated part.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a processing method in which aprocessing is carried out that deforms a part of an image fiber in theradial direction, wherein the deformation of the cores forming the imagefiber and functioning as pixels becomes substantially identical for allthe cores, and the improvement in the image quality at the center regionand the peripheral region of the image fiber in the radial directionbecomes substantially identical.

[0003] 2. Description of the Related Art

[0004] Conventionally, the center region of an image fiber used in afiber scope, for example, is heated and softened, and by carrying out atwisting process in which the image fiber is twisted or a bendingprocess in which the image fiber is bent, improvement in the imagequality of the transmitted image and inversion or the like of imagedirection can be carried out.

[0005] In particular, where the object is improvement of the quality ofthe transmitted image, there is a method of applying a twist having asmall pitch to a part of the image fiber. Thereby, the core thatfunctions as a pixel is deformed, the clad mode of the transmitted lightfrom the deformed part of this core is dispersed to the outside, thelight that becomes noise is eliminated, and thereby, the contrast in theimage can be increased.

[0006] However, when applying such a twist with a small pitch, as isschematically shown in FIG. 7, the amount of deformation of the core atthe center part 1 a of the image fiber 1 in the radial direction becomessmaller than the amount of deformation of the core at the peripheralregion 1 b. Thus, when trying to sufficiently improve the image qualityat the center region 1 a, if the amount of the twist becomes large, theamount of deformation of the core at the peripheral region 1 b becomesexcessive, and there is a concern that the image may be broken up, andthe quality of the image at the peripheral region 1 b, to the contrary,deteriorates.

[0007] For example, Japanese Patent No. 2925173, Japanese UnexaminedPatent Application, First Publication, No. 2000-185931, JapaneseExamined Patent Application, Second Publication, No. Hei 6-42008, andJapanese Unexamined Patent Application, First Publication, No. Hei10-123411 disclose a related art to carrying out such a deformationprocess on image fibers.

[0008] Thus, the problem to be solved by the present invention isapplying a deforming process to a part of the image fiber, and whenimplementing an improvement of the quality of the transmitted image, theimprovement of the image quality at the center region and the peripheralregion of the image fiber in the radial direction is substantiallyidentical, and thereby a uniform improvement of the entire screen isattained.

SUMMARY OF THE INVENTION

[0009] In order to achieve the object, the present invention provide aprocessed image fiber comprising a processed part which is obtainable bydeforming a part of the image fiber having a plurality of cores thatfunction pixels in the radial direction such that the deformation of allcores is substantially identical.

[0010] In the processed image fiber, it is preferable for the processedpart to be twisted in circumferential direction such that thedeformation of all cores is substantially identical while thedeformation in the radial direction.

[0011] In addition, in the processed image fiber, it is also preferablefor the processed part to be covered by a protective member.

[0012] According to the processed image fiber, the improvement of theimage quality in the peripheral region and the center region in theradial direction of the processed image fiber can be uniformly carriedout. Therefore, it is possible to obtain a high quality image over theentire screen.

[0013] In addition, in order to achieve the object, the presentinvention provide a processing method comprising the steps of: heating apart of the image fiber having a plurality of cores that function aspixels; deforming the heated part in the radial direction thereof; andforming a processed part having a deformation of all cores that issubstantially identical.

[0014] In the processing method, it is preferable for the heated part tobe twisted such that the deformation of all cores is substantiallyidentical while deforming in the radial direction thereof.

[0015] According to the processing method of the image fiber of thisinvention, the improvement in the image quality in the peripheral regionand the center region in the radial direction of the image fiber can becarried out uniformly, and thereby it is possible to manufacture animage fiber that can transmit a high quality image over the entirescreen.

[0016] Furthermore, in order to achieve the object, the presentinvention provide a processing apparatus for an image fiber comprising:a heating device that heats a part of an image fiber; and a deformingdevice that applies a deformation to a part of the image fiber that hasbeen heated by the heating device in the radial direction thereof.

[0017] In the processing apparatus, it is preferable to further comprisea twisting device that applies a twist to a part of the heated imagefiber.

[0018] According to the processing apparatus for the image fiber of thisinvention, the above-described processing method can be easilyimplemented.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019]FIG. 1 is a side view having a portion cut away schematicallyshowing an example of the processed image fiber of the presentinvention.

[0020]FIG. 2 is a perspective diagram showing a portion of thedeformation in the radial direction in the present invention.

[0021]FIG. 3 is a perspective drawing showing another example of thedeformation in the radial direction in the present invention.

[0022]FIG. 4 is a schematic structural drawing showing an example of theprocessing apparatus of the present invention.

[0023]FIG. 5 is a chart showing an example of the effect of theimprovement in the image quality in the present invention.

[0024]FIG. 6 is a chart showing the effect of the improvement in theimage quality according to the conventional technology.

[0025]FIG. 7 is an explanatory drawing for explaining the typical amountof deformation in the peripheral region and the center region of theimage fiber.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Below, the invention will be explained in detail.

[0027]FIG. 1 schematically shows an example of the processed image fiberof the present invention. In FIG. 1, reference number 1 denotes theimage fiber. In this image fiber 1, a plurality of silicon core-claddingtype optical fibers are bundled, fused, fastened, and integrated whilepreserving their alignment. The image fiber 1 has a circularcross-section, a diameter of 0.1 to 5 mm, and is used in a typicalfiberscope or the like.

[0028] A processed part 2 is formed on a portion of this image fiber 1in the longitudinal direction, and thereby the image fiber 1 becomes theprocessed image fiber.

[0029] In this processed part 2, this portion of the image fiber 1becomes deformed in the radial direction thereof, or is both deformed inthe radial direction thereof and twisted in the circumferentialdirection. In addition, the amount of deformation of each of the coresin the processed part 2 becomes substantially identical at all locationsfrom the center region to the peripheral region of the image fiber 1.

[0030] Here, as shown, for example, in FIG. 2, “deformed in the radialdirection” denotes a state wherein the image fiber 1 is gently benttwice within an identical plane, a type of step is formed, and thecenter axis of the image fiber 1 is offset in parallel, or as shown inFIG. 3, a state wherein the image fiber 1 is gently twisted, it acquiresa small spiral shape, and the center axis of the image fiber 1 isfolded.

[0031] In addition, “twisted in the circumferential direction” denoteseither fixing one of the portions of either side of the part of theimage fiber 1 that will become the processed part 2 and turning theother in the circumferential direction, or turning both sides inmutually opposite directions in the circumferential direction.

[0032] The amount of this turning when twisting in this circumferentialdirection is typically about 0.3 to 1 rotations (in terms of rotationangle, from 100 to 360 degrees), but this range is not limiting, anddepending, for example, on the degree of the improvement of the imagequality, can be appropriately determined. In particular, when the amountof rotation is 0.5 of one rotation, the direction of the image can beinverted, and the lens system can be simplified when incorporated intoan image scope.

[0033] Because a deformation in the radial direction may be applied, orboth a deformation in the radial direction and a twisting in thecircumferential direction may be applied simultaneously to the processedpart 2, as is shown schematically in FIG. 1, each of the optical fibers2 a of the actual processed part 2 acquire the shape of a spiral.

[0034] In addition, the length of the processed part 2 is about 5 to 50mm, the thickness is about 0.1 to 10 mm, but these ranges are notlimiting.

[0035] Furthermore, the deformation of the core at this processed part 2is substantially identical at all locations of the image fiber 1 in theradial direction. While the position of each core changes and acquires aspiral shape in the longitudinal direction thereof due to thedeformation in the radial direction and the twisting in thecircumferential direction, the cross-sectional shape of each core itselfhas almost no deformation, warping, or strain. In addition, referencenumeral 3 in FIG. 1 denotes the protective member that protects theprocessed part 2. Because the formation of the processed part 2 involvesheating with a heat source such as an oxy-hydrogen burner, an electricheater, laser light, an electrical discharge or the like, thisprotective member 3 is provided in order to protect the optical fiberwhen it is exposed after removal of the protective covering.

[0036] For this protective member 3, synthetic resins such as siliconresin, polyimide resin, epoxy resin, urethane resin, or olefin resin canbe used; metals such as stainless steel, aluminum alloys, or copperalloys can be used; ceramics such as oxidized aluminum, oxidizedsilicon, or oxidized zirconium can be used; glasses such as quartz orthermo resistant glass can be used; or fiber reinforced plastics and thelike can be used. In addition, when the protective member 3 is formed bybeing covered with the above-described synthetic resins, a relativelysoft one is obtained. A relatively rigid protective member 3 is obtainedby forming a pipe shape or chute shape that comprise metal, ceramic,glass, fiber reinforced plastics, or the like, and mounting these ontothe processed part 2.

[0037] Next, the processing method for the image fiber will beexplained.

[0038]FIG. 4 shows an example of the processing apparatus used in thisprocessing method. In the figure, reference numeral 11 denotes a first Vgroove base. A second V groove base 12 is provided disposed at apredetermined spacing from this first V groove base 11, and the firstand second V groove bases 111 and 12 are installed on a stage (notillustrated). In addition, the V groove bases 11 and 12 are both squareshaped plates, and in the center of the upper surface, one straight Vgroove is formed. The image fiber 1 is accommodated in this V groove. Inaddition, a first restraining member 17 and a second restraining member18 that fasten the image fiber 1 accommodated in the V grooves arerespectively provided on the first V groove base 111 and the second Vgroove base 12.

[0039] Between and below the first V groove base 11 and the second Vgroove base 12, as a heat source an oxy-hydrogen burner 13 is providedso as to be able to move. In addition, a target 14 for determining therotation position is provided on the side of the first V groove base 11.Furthermore, on the side of the second V groove base 12, a twistingapparatus 15 is provided. This twisting apparatus 15 applies a twistingto the image fiber 1 by holding the image fiber 1 and rotating it in thecircumferential direction.

[0040] In addition, at the side of the twisting apparatus 15, atelevision camera 16 is provided. This television camera 16 picks up thetarget 14 via the image fiber 1 as an image, and monitors the degree ofthe twisting, or in other words, the degree of rotation, of theprocessed part 2. Depending on the results of this rotation, the degreeof the twisting of the image fiber 1 due to the twisting apparatus 15can be controlled.

[0041] Furthermore, the first V groove base 11 and the second V groovebase 12 are disposed so as to have a positional relationship slightlyoffset in parallel or a positional relationship that is slightly shiftedso that the center line of the V groove of the other V groove base isnot aligned. As shown in FIG. 4, they have a positional relationshipthat is offset in parallel in a vertical direction, and in order toclarify this relationship, it is illustrated in a slightly exaggeratedmanner.

[0042] In the structure of this processing apparatus, the oxy-hydrogenburner 13 forms the heating device, the first and second V groove bases11 and 12 form the deformation device, and the twisting apparatus 15forms the twisting device.

[0043] To process the image fiber using this processing apparatus,first, the protective covering of the processed part of the image fiber1 is removed, the part 1 c of the image fiber 1 having the protectivecover removed is positioned over the oxy-hydrogen burner 13, the imagefiber 1 is accommodated in each of the V grooves of the first and secondV groove bases 11 and 12, and simultaneously inserted into and held bythe twisting apparatus 15.

[0044] Next, the image fiber 1 accommodated in each of the V grooves ofthe first V groove base 11 and the second V groove base 12 is pressedbetween the first restraining member 17 and the second restrainingmember 18. At this time, in the first restraining member 17, the imagefiber 1 is rigidly pressed and fastened so that it cannot rotate, and inthe second restraining member 18, the image fiber 1 is gently pressedand fastened to a degree that does not prevent its rotation.

[0045] Next, the processed part 1 c of the image fiber 1 is heated bythe oxy-hydrogen burner 13. At this time, the oxy-hydrogen burner 13 ismoved back and forth longitudinally along the image fiber 1, and a rangebroader than that of the processed part 1 c is heated uniformly.

[0046] The processed part 1 c of the image fiber 1 softened due to theheat is naturally deformed in the radial direction because, as describedabove, the first V groove base 11 and the second V groove base 12 aredisposed so as to be offset. That is, the image fiber 1 is forcibly bentand elastically deformed before heating, but after having been heated,due to softening, this elastic deformation state transforms to a plasticdeformation state, and a permanent deformation remains in the radialdirection.

[0047] Simultaneously, the other end of the image fiber 1 is rotated bythe twisting apparatus 15, and the twisting is applied to the softenedprocessed part 1 c. At this time, the amount of twisting is adjustedwhile monitoring the image of the target 14 picked up by the televisioncamera 16. When a predetermined twisting has been applied, the heatingby the oxy-hydrogen burner 13 is ended.

[0048] Finally, as described above, the processed part 2 formed in thismanner is covered with the protective member 13, and thereby theprocessed image fiber is manufactured.

[0049] In addition, in the processing apparatus shown in FIG. 4, adeformation can simply be applied only in the radial direction of theimage fiber 1 by using a processing apparatus omitting the twistingapparatus 15.

[0050] In such a processed image fiber, a deformation in the radialdirection is applied or a deformation in the radial direction and atwisting in the circumferential direction are simultaneously applied tothe processed part 2, and because the deformation of each of the coresis of a substantially identical degree in the peripheral region andcentral region of the image fiber 1, the image quality is improved dueto the noise light scattering uniformly and the image quality over theentire screen is improved to the same extent.

[0051] In addition, by applying the twisting, the direction of the imagecan be changed arbitrarily, and when used as a fiberscope, the objectivelens system or the ocular lens system can be simplified. Furthermore,because the diameter of the processed part 2 does not increase, thediameter when serving as an image fiber 1 does not increase, and theprocessed part 2 does not lengthen.

[0052] In addition, in comparison to implementing only a twisting or abending process, variation in the amount of light occurs withdifficulty. Furthermore, because a small processed part 2 can be formed,if a protective part comprising a synthetic resin is provided, one canbe manufactured that exhibits a flexibility identical to that of anormal image fiber.

[0053]FIG. 5 shows the contrast as a transmission characteristic of theprocessed image fiber obtained in this manner. In FIG. 5, (a) shows thecontrast at the peripheral region of the processed image fiber; (b)shows the contrast at the center region of the processed image fiber;and (c) shows the contrast of the image fiber before processing.

[0054] From the graph in FIG. 5, it can be understood that the contrastwas improved uniformly over the screen as a whole in this processedimage fiber.

[0055] In contrast, FIG. 6 shows the contrast of an image fiber havingapplied only the conventional strong twist. In FIG. 6, (a) shows thecontrast at the peripheral region of the image fiber; (b) shows thecontrast at the center region of the processed image fiber; and (c)shows the contrast of the image fiber before twisting.

[0056] From the graph in FIG. 6, it can be understood that the degree ofimprovement in the contrast at the peripheral region and the centralregion differs in the image fiber having only this twisting applied.

[0057] In the present invention, the processing method and apparatustherefore that have been described above can also take various otherforms, such as those described below.

[0058] First, the processing of the processed part 2 is possible withapparatuses other than that described above. For example, manualprocessing is also possible. In addition, the oxy-hydrogen burner 13 canbe fixed and the image fiber 1 can be moved in the longitudinaldirection thereof.

[0059] In addition, a structure is possible in which the twistingapparatus 15 is omitted, the second V groove base 12 is made to rotate,and thereby the twisting is applied. In addition, the twisting apparatus15 and the second V groove base 12 can be integrated. Furthermore, inaddition to the method in which the deformation in the radial directionis applied by offsetting the two V groove bases 11 and 12, the two Vgroove bases 111 and 12 can be disposed coaxially, and the image fiber 1that is in a heated state can be deformed in the radial direction byapplying a force to the processed part of the image fiber 1 using an armfor deformation.

[0060] It is also possible to dispose either only the first V groovebase 11 or the second V groove base 12 on stage that can move in threedimensions, and apply the deformation to the image fiber 1 in the radialdirection by appropriately moving the first V groove base 11 or thesecond V groove base 12 in the X direction, Y direction, or Z direction.Furthermore, instead of offsetting the two V groove bases 111 and 12,the deformation in the radial direction can be applied by offsetting inparallel or diagonally the position of the V groove formed in the Vgroove bases 11 and 12.

[0061] In addition, the mechanism for holding the image fiber 1 is notlimited to a combination of V grooves and the first and secondrestraining members 17 and 18. Any structure is possible if it holds theimage fiber. Furthermore, the shape of the processed part 2 can be acoil spring made by enlarging the spiral shape.

What is claimed is:
 1. A processed image fiber comprising a processedpart which is obtainable by deforming a part of the image fiber having aplurality of cores that function pixels in the radial direction suchthat the deformation of all cores is substantially identical.
 2. Aprocessed image fiber according to claim 1, wherein the part of theimage fiber is twisted in circumferential direction such that thedeformation of all cores is substantially identical while thedeformation in the radial direction.
 3. A processed image fiberaccording to any one of claims 1 and 2, wherein the processed part iscovered by a protective member.
 4. A processing method comprising thesteps of: heating a part of the image fiber having a plurality of coresthat function as pixels; deforming the heated part in the radialdirection thereof; and forming a processed part having a deformation ofall cores that is substantially identical.
 5. A processing methodaccording to claim 4, wherein the heated part is twisted such that thedeformation of all cores is substantially identical while deforming inthe radial direction thereof.
 6. A processing apparatus for an imagefiber comprising: a heating device that heats a part of an image fiber;and a deforming device that applies a deformation to a part of the imagefiber that has been heated by the heating device in the radial directionthereof.
 7. A processing apparatus for an image fiber according to claim6, wherein further comprises a twisting device that applies a twist to apart of the heated image fiber.